This chapter provides a running commentary on the highly contested Epistle to Theodore, discovered, reportedly, by Morton Smith in the Mar Saba monastery in 1958. If proved authentic, the Epistle to Theodore would provide important details about Carpocrates and his relation to a document called Mystic Mark (an expanded version of the Gospel of Mark meant for initiates). The commentary, therefore, focuses on the issue of the epistle’s authenticity. The author of the Epistle to Theodore was dependent on Eusebius in at least three ways: (1) in his knowledge that Clement was a presbyter, (2) in his knowledge that the evangelist “Mark” came to Alexandria, and (3) in his reference to the gospel of Mark as a “spiritual gospel.” The author of the Epistle to Theodore may also have depended on Epiphanius for his innuendo about Jesus being involved in homoerotic activity. In conclusion, one must reject the authenticity of the Epistle to Theodore. It cannot add to our knowledge of second-century Carpocratian Christianity.